COPPER PROCESSING
industry to be the first to adopt new technology , referencing BASF ’ s experience with LixTRA to date .
BASF has carried out numerous column and mini heap trials around the world over the last three years , increasing copper recoveries by over 40 % in some cases ; however , it only recently gained its first commercial account in Chile .
“ We understand the risks associated with applying new chemistry and especially concerns around compatibility with upstream and downstream processes ,” Taute said . “ However , BASF has been a major supplier of copper SX reagents to the downstream SX process for over 50 years , so it is this reputation , knowledge and experience coupled with numerous proof-ofconcept trials that we believe will eventually mean the technology will become mainstream .”
He concluded : “ The beauty of both technologies is in the simplicity of their application ; a small pumping system for LixTRA and a Moleaer nanobubble generator coupled to an oxygen source for the nanobubbles to easily integrate into existing systems . It ’ s exciting , new and sustainable extraction technology , and we are hopeful of making big strides in 2023 .”
Low-carbon leaching
The excitement around chalcopyrite leaching Taute mentioned is tangible at several Freeport- McMoRan sites , with the company advancing new applications , technologies and data analytics as part of a plan to improve copper recovery from its leach processes in North and South America .
One of the solutions currently under the Freeport microscope is Jetti Resources ’ patented catalytic technology , the mining company recently confirmed to IM .
In its December quarter and 2022 annual results , the leading copper miner – which has received Copper Mark accreditation at all its copper production sites – said it believed the leach innovation initiatives it was pursuing provided potential opportunities to produce incremental copper from its large existing leach stockpiles and lower-grade material currently classified as waste .
Freeport has been exploring the potential for incremental low-cost additions to its production and reserve profile for some time , saying in its latest results release that it had identified opportunities to achieve an annual run rate of 200 MIb / y ( 90,718 t / y ) of copper through these initiatives by the end of 2023 .
Freeport has a long history of copper leaching production with its Americas division , which includes assets such as Morenci and Cerro Verde , having developed and implemented industryleading technologies for leaching of oxide ores .
The company has been pursuing internal and external initiatives to expand this leading position , focused on traditional ores and sulphide orebodies like chalcopyrite . This is where Jetti ’ s technology comes in . The Colorado-based company has developed catalytic technology to allow for the efficient and effective heap and stockpile leach extraction of copper . This bolts onto existing SX / EW leaching plants so it can be deployed rapidly with limited capital expenditure . Because it uses no heating or grinding , it also comes with low operational costs .
In addition , there are huge environmental benefits from using leaching over pyrometallurgy .
A Freeport spokesperson confirmed to IM that the company was in a trial of the Jetti technology through “ a commercial installation ” at its Bagdad mine in Arizona . This mine is one of its major leaching test hubs , with the company targeting over 3 MIb / y of incremental copper cathode production from the open-pit copper mine through this work .
Bagdad has a 77,100 t / d concentrator that produces copper and molybdenum concentrate , an SX / EW plant that can produce approximately 6 MIb / y of copper cathode from solution generated by low-grade stockpile leaching and a pressure-leach plant to process molybdenum concentrate .
The spokesperson added : “ There is potential to expand production via the treatment of additional stockpiles at Bagdad in the future based on results .”
Even more recently , Jetti confirmed that Freeport ’ s majority-owned El Abra mine in Chile was using its technology .
The use of Jetti ’ s technology is one of several leaching initiatives the company is pursuing , with all of them geared towards not only adding lowcost production to Freeport ’ s large production base , but also achieving a lower carbon footprint .
Jetti , which Freeport is an investor in , has been conducting a carbon footprint study and Life Cycle Assessment ( LCA ) of its technology , with the LCA including analyses of typical copper mining operations without Jetti ’ s technology and a mining operation with Jetti ’ s technology installed .
Jetti has also committed to starting to track water usage and waste at all its operations and sites , which includes the installation it has at Capstone Copper ’ s Pinto Valley operation , also in Arizona .
In addition to Freeport , Teck Resources has taken an interest in Jetti ’ s technology having signed an agreement for the evaluation of the solution at a number of Teck ’ s assets with potential copper resources outside of existing mine plans .
As to Freeport ’ s wider leaching plans , the company said it was looking to use data analytics to provide new insights to drive additional value , while new applications to retain the heat in the stockpiles were “ yielding results ”.
The company has assessed it has some 38,000 MIb of contained copper in leach stockpiles deemed “ unrecoverable ” by traditional leach methods . Of this amount , about 50 % is from the massive Morenci mine , which already has leaching production capacity of 900 MIb / y of copper .
Moving the copper industry forward
Solvay says it remains focused on reagent-based innovation for copper producers , with its innovation increasingly linked to both performance and sustainability .
To deliver high-performing and eco-conscious solutions , Solvay is leveraging its Smart Mining Chemistry portfolio and harnessing the power of digital solutions to further assist copper producers in improving productivity and extracting more value from orebodies at an unprecedented speed .
The company ’ s developments fit into a few key areas , namely : improved selectivity , digital developments , and safety / sustainability improvements associated with extracting and recovering copper .
In the first category , iron selectivity continues to be viewed as a critical aspect in copper purification , which must be addressed before moving to EW . Solvay ’ s ACORGA ® copper extractants remain a reagent reference for copper SX , the company says , offering higher copper / iron selectivity and a reduction in the amount of iron introduced into the tank house , which benefits recoveries and energy use .
ACORGA , Solvay says , is a versatile product family , which is continually adapted to meet customer- and region-specific needs .
“ For instance , ACORGA M5910 has been adopted as the optimal reagent for most US operating conditions and offers the highest Cu : Fe selectivity in the industry ,” the company said . “ To meet the needs of more challenging pregnant leach solution ( PLS ) feeds , Solvay recently supported a major US-based copper producer by developing ACORGA M5490 , which has become the operation ’ s reference product due to its outstanding selectivity and performance at a lower pH .”
In other cases where the geological aspects of the ore and the operation demand different chemistries , such as in Africa , ACORGA OPT5540 is finding favour thanks to its optimised copper net transfer and Cu : Fe selectivity compared with other ketoxime formulations .
In Chile , ACORGA Nitration-Resistant ( NR ) extractants enable the efficient hydro-processing of caliche-type copper minerals , which can generate high-nitrate PLS solutions . The ACORGA
20 International Mining | MARCH 2023